Oil fuse cut-out



May 18 1937. E, PAPP 2,080,739

OIL FUSE CUT-OUT Filed June 12, 1934 Zmventor Andrew I P/af (Ittomeg III Patented May 18, 1937 PATENT OFFICE OIL FUSE CUT-OUT Andrew E. Papp, Chicago, Ill., assignor to G & W

Electric Specialty 00., Chicago, 111., a corporation of Illinois Application June 12, 1934, Serial No. 730,191

23 Claims.

My invention relates to fuses or cutouts for opening an electric circuit on an overload current.

One of the objects of the invention is to provide a simple, practical and advantageous fuse or cutout.

Another object of the invention is to arrange for a quick and efiective opening of the circuit upon the blowing of the fuse.

Another object of the invention is to provide a simple, practical and advantageous fuse or cutout utilizing oil or similar insulating material in connection with the fuse and its operation.

Another object of the invention is to utilize the high pressure caused by the fuse explosion to increase the insulating strength of the dielectric, such as oil, in which the fuse is immersed, and also to utilize that pressure for rapidly and effec- Lively quenching, deionizing, cooling andsevering the are by a stream of cool, rapidly moving, high pressure oil.

Other objects of the invention will appear and be pointed out hereinafter.

In the accompanying drawing, Figure 1 shows a fuse cutout embodying my present invention, partly in elevation and partly in vertical section; and

Figure 2 is a view taken in the plane represented by line 2-2 of Figure 1 showing the loop formed at the ends of the springs of the device.

Referring to the drawing, I show a fuse or cutout having a box or case I preferably made of steel or some similar material of high mechanical strength, said box having side walls 22 and a bottom 3. This box or casing is adapted to hold oil or similar material which is intended to substantially fill the same, the upper level of the oil or similar material being shown by way of illustration at I.

A pair of inlets 55 are shown arranged in apertures 6-6 in the bottom of box I, being preferably held in position by holding members 1-! held in position by bolts 88.

These inlet members 5 are preferably of a tubular character, as shown in the sectional view at the right-hand side of the drawing, and each one receives a cable In which extends upwardly and has its upper end bared to expose the conductor I I, which conductor I I is inserted into a terminal I2. This terminal I2 has a spindle I3 which extends out through the upper end of the insulator and fits into a socket I4 adapted to support and be connected with one end of a fuse assembly.

This fuse assembly involves fuse holding springs I5 and contact shoes I6, which make sliding contact with metal shoes I l at the top of socket member I4, so that shoes I6 may slide on members I4 to permit insertion and withdrawal of the fuse assembly. Springs I5 are normally held in their uppermost position by the fuse I1 which passes through loops in the upper ends of the springs and hasits ends connected between contact shoes I6 and plates I5 These loops are formed by bending portions II over the main part of the springs but leaving a space therebetween to receive the fuse, as shown in Figure 2.

'I'he'springs do not have to be removed when renewing the fuse. Thus fuse I1 is connected at its opposite ends to springs I5I5 which are adapted to spring or move outwardly away from one another when not held by the fuse, as shown by dotted lines I5, whereby the fusewill be normally held by said springs I5-I5 and will nor mally hold the springs in turn under tension, as shown in full lines in Figure l, but also whereby when the fuse blows the two springs I5-I5 will be released and will swing or fly outwardly away from one another so as to materially increase the gap or opening between the upper ends of said springs, thereby assisting in destroying the are due to breaking the circuit.

As a matter of further improvement, I preferably provide an inner fuse chamber which may be formed by a tubular insulator 20 properly mounted in the interior, preferably the central portion of the case I, said insulator conveniently supporting at its lower end plates I5 which by screws 2| hold springs I5 in place and also supporting contact shoes I6 by means of screw bolt 22 and holding fuse ends in place between plates I5 and the contact shoes I6. The insulating member 20 forming the fuse chamber is preferably provided with side openings 23-23 through which the fuse is extended, and these'openings 23 are preferably conical or tapering, as shown in the .drawing. Oil within the casing I will, of course,

find its way into the interior of insulator or casing 20 through openings 23, and will fill or substantially fill said member 20 so that the fuse I! will be not only extended between spring terminals I 5-I 5, but will also be substantially encased in a closed chamber, the insulator 20, and will also be immersed in oil or other insulating material which. may be used.

Thus, when the fuse operates not only are the terminals separated by the outward springing movement of spring I5I5, but furthermore there is a compression due to the pressure of the explosion of the fuse in a closed chamber when it operates; and furthermore, oil will be forced or squirted outwardly through side openings 23 and thereby tend to choke off the are at the neck of the orifice by a high pressure stream of cool deionizing oil of high dielectric strength. All these three actions contribute to a highly efficient and effective fuse operation, breaking the circuit and extinguishing the arc.

The springs being very light, there is quick action and very little inertia in the spring movement to move the ends of the burning fuse outwardly with great rapidity. The explosive pressure on the oil increases its dielectric strength and so tends to extinguish the arc; and the stream of high pressure oil flowing through the two side orifices rapidly and effectively quenches, deionizes, cools and severs the arc. The fuse explosion is retained in a small, strong secondary fuse chamber so that the high pressure generated inside by such explosion is not immediately transferred to the outer chamber, but is throttled down somewhat because of the small size of the fuse orifices in the secondary fuse chamber wall. This protects the outside steel casing from being suddenly exposed to a disruptive pressure and makes the whole assembly easier to vent at the top.

The lower end of fuse-holding insulator 20 is preferably made open and provided with screwthreads so that a plug 25 likewise threaded may be screwed into said insulator and thereby maintain a normal closed fuse chamber when desired, but will also permit the lower end of the fuse chamber to be opened and drained of oil or other operations performed, as may be desired. In order to permit placing the fuse and the fuse assembly in place, the insulator 20 is preferably mounted on a top 26 mounted upon closure member 26 arranged upon the casing l and adapted to be turned or rotated for locking the fuse and its assembly in place, and unlocking the same, the insulator 20 being conveniently supported by top 26 through the medium of a threaded member 21 which may be screwed into the upper end of member 20 and also into a threaded socket 28 on cover 26.

For locking purposes, an annular member 30 is preferably secured to closure member 26 and provided with a vertical slot 3| through which a lock pin 32 on the fuse assembly may pass, so that to put the device in place the lock pin 32 may be allowed to pass down through slot 3| and then cover 26 may be turned so as to move said pin 32 underneath member 30 and thereby lock the cover and fuse with its assembly in position. The fuse assembly or holder must be inserted when the fuse is in an off position, as it is impossible to insert that holder or assembly when it is in an on position and also impossible to remove it at that time. Thus, the cover and fuse holder are inserted when the fuse is in the off position and then the cover is turned so as to make the fuse contacts and bring the fuse into the on position.

The inlets 5 for the cables are preferably involved in an insulating tube or member 35 surrounding the terminal spindle l3 and also having an enlarged portion to surround the terminal l2, and these inlets also preferably involve a metallic body member 36 having shoulders 31 fitting against the under side of the casing I and containing the cable sheath and suitable insulating material or compound 38 which may be inserted through plug members 39. Another metallic member 40 is preferably arranged below member 36 and provided with a wipe joint 4i making connection with cable l0. To permit rotation of the cover 26, a tubular member is provided to receive a bar by which the cover may be turned.

It will be understood that changes and modifications may be made without departing from the spirit of the invention.

What I claim is:

1. A device of the class specified comprising a chamber containing a mobile insulating material, spring fuse mountings therein, said mountings comprising strip springs providing terminals for opposite ends of the fuse and arranged to spring away from one another when the fuse blows, and means whereby insulating material will be directed upon said spring terminals when the fuse blows.

2. A device of the class specified comprising an outer casing providing a chamber for mobile insulating material, a second casing arranged within the outer casing to provide a fuse chamber, said second casing having small side openings through which the fuse may be extended, and springs providing fuse terminals for connection with the ends of the fuse passing through said side openings, whereby the springs will separate the fuse terminals when the fuse blows and the fuse explosion will produce high pressure to increase the dielectric strength of the insulating material and assist in extinguishing the are.

3. A device of the class specified comprising a metal chamber, spring terminals for a fuse therein, and a casing providing a fuse chamber to enclose the fuse between the terminals, said casing having openings through which the fuse passes when attached to the terminals, whereby when the fuse blows the spring terminals move away from one another and increase the arc gap of the fuse and also whereby the enclosed chamber produces an explosive force which tends to extinguish the arc and also whereby insulating material will be forced or squirted through said chamber openings to produce a stream of insulating material to assist in extinguishing the arc.

4. A device of the class specified comprising a metal oil casing, inlets for cables extending up through the bottom of said casing and having their upper ends provided with a fuse-holding device, spring members arranged to form outwardly springing terminals for a fuse which is l mounted and connected between said spring terminals, and an insulating member having an oil chamber and arranged between the fuse terminals and provided with side openings so that the fuse may extend through said side openings and said chamber when it is attached to said spring terminals.

5. A device of the class specified comprising a metal oil casing, inlets for cables extending up through the bottom of said casing and having their upper ends provided with a fuse-holding device, spring members arranged to form outwardly springing terminals for a fuse which is mounted and connected between said spring terminals, and an insulating member having an oil chamber and arranged between the fuse terminals and provided with side openings so that the fuse may extend through said side openings and said chamber when it is attached to said spring terminals, said side openings on said fuseholding member being outwardly flared or conical in shape.

6. A device of the class specified comprising a metal oil casing, inlets for cables extending up through the bottom of said casing and having their upper ends provided with a fuse-holding device, spring members arranged to form outwardly springing terminals for a fuse which is mounted and connected between said spring terminals, an insulating member having an oil chamber and arranged between the fuse termi nals and provided with side openings 'so that the fuse may extend through said side openings'and said chamber when it is attached to said spring terminals, and means for mounting said fuse and holding assembly so that the same may be inserted into and removed from the top of the oil containing casing.

7. A device of the class specified comprising a metal oil, casing, inlets for cables extending up through the bottom of said casing and having their upper ends provided with a fuse-holding device, spring members arranged to form outwardly springing terminals for a fuse which is mounted and connected between said spring terminals, an insulating member having an oil chamber and arranged between the fuse terminals and provided with side openings so that the fuse may extendthrough said side openings and said chamber when it is attached to said spring terminals, and means for mounting said fuse and holding assembly so that the same may be inserted into and removed from the top of the oil containing casing, said assembly being mounted on the cover of the device which is arranged to rotate and is provided with looking devices which may be caused to interlock by rotation of the cover.

8. A device of the class specified comprising an outer casing forming a chamber for liquid insulating material, an inner casing forming a fuse chamber, and springs on the opposite sides of the I inner casing providing spring-actuated fuse terminals for the opposite ends of the fuse, said springs being mounted on the outside of the inner casing.

9. A device of the class specified comprising an outer casing forming a chamber for liquid insulating material, an inner casing forming a fuse chamber, and springs on the opposite sides of the inner casing providing spring-actuated fuse terminals for the opposite ends of the fuse, said inner casing being provided with side apertures through which the fuse extends and said springs being mounted on the outside of said cas ing and engaging the fuse ends on the outside of said casing at the outer ends of said side apertures, and being arranged to spring outwardly away from said casing when the fuse blows.

10. A device of the class specified comprising an outer casing providing a chamber for liquid insulating material, an inner casing providing a fuse chamber, said inner casing being in the form of a vertically arranged tubular member having side openings through which the fuse may be extended and through which the liquid in the outer chamber may pass, and terminals for the fuse mounted on the outside of said tubular member adjacent the outer ends of said side openings.

11. A device of the class specified comprising an outer casing providing a chamber for liquid insulating material, an inner casing providing a fuse chamber, said inner casing being in the form of a vertically arranged tubular member having side openings through which the fuse may be extended and through which liquid insulation may pass, and terminals for the fuse mounted on the outside of said tubular member, said terminalsbeing provided with spring members carried by and mounted upon the outside of said tubular casing and having their free ends arranged to spring outwardly away from the casing when the fuse blows.

12. A device of the class specified comprising an outer casing providing a chamber for liquid insulating material, an inner casing providing a fuse chamber, said inner casing being in the form of a vertically arranged tubular member having side openings through which the fuse may be extended, and terminals for the fuse mounted on the outside of said member, said tubular casing having its lower end provided with a removable plug for drainage purposes.

13. A device of the: class specified comprising an outer casing providing a chamber for liquid insulating material, an inner casing providing a fuse chamber, said. inner casing being in the form of a'vertically arranged tubular member 14. A device of the class specified comprising an outer casing providing a chamber for liquid insulating material, an inner'casing providing a fuse chamber, said inner casing being in the form of a vertically arranged tubular member b aving side openings through which the fuse may be extended, and terminals for the fuse mounted I on the outside of,.said tubular member, said tubular casing being arranged for bodily insertion into and removable from the outer casing, and a cover for the outer casing to which said tubular casing is attached for bodily removal when the cover is taken off.

15. A device of the class specified comprising an outer casing providing a chamber for liquid insulating material, an inner casing providing a fuse chamber, said inner casing being in the form of a vertically arranged tubular member having side openings through which the fuse may be extended, and terminals for the fuse mounted on the outside of said tubular member, said tubular member being arranged for bodily insertion into and removable from the outer casing, a

cover for the outer casing to which said tubular casing is attached for bodily removal when the cover is taken off, and locking devices for locking the cover in position on the outer casing.

16. A device of the class specified comprising an outer casing providing a chamber for liquid insulating material, an inner casing providing a fuse chamber, said inner casing having side openings for the fuse, springs mounted on the outside of the inner casing and engaging the ends of the fuse which pass through said side openings, and co-operating contact devices on the outer and inner casings for permitting the bodily mounting and dismounting of the inner casing with its fuse and contact devices.

17. In a device of the class specified, a fuse chamber adapted to contain liquid insulating material and having side apertures between and through which the fuse is extended, and springactuated fuse terminals located adjacent said side apertures and arranged to spring outwardly from one another when the fuse blows.

18. A device of the class specified comprising an outer casing providing a chamber for liquid insulating material, an inner casing providing a fuse chamber, said inner casing having side openings for the fuse, springs mounted on the outside of the inner casing and engaging the ends of the fuse which pass through said side openings, and co-operating contact devices on the outer and inner casings for permitting the bodily mounting and dismounting of the inner casing with its fuse and contact devices, said last mentioned devices comprising contact shoes on the inner casing connected with the fuse, and springs and other contact shoes on the outer casing co-operating with said first mentioned contact shoes and connected with conductor terminals in the outer casing.

19. In a device of the class specified, an inner casing providing a fuse chamber, strip springs mounted thereon and having their free ends adapted to serve as terminals for the fuse, plates holding said strip springs on said inner casing and shoes holding the fuse in contact with said plates.

20. A fuse comprising an outer casing providing a chamber for liquid insulating material, an inner casing providing a fuse chamber, said inner casing having opposite openings through which the fuse may be extended and through which the liquid in the outer chamber may pass, and spring terminals for said fuse mounted on the outside of said inner casing.

21. A fuse comprising an outer casing providing a chamber for mobile insulating material, an inner casing providing a fuse chamber and communicating with said outer chamber through a restricted opening, and a fuse disposed in said last-named chamber extending into said restricted opening and having spring means providing terminals therefor exterlorly of said inner casing, said fuse, fuse chamber and restricted opening being so constructed and arranged that when said fuse blows the mobile insulating material within aoaonso said inner chamber is forced outwardly through said restricted opening thereby increasing the fuse gap.

22. A fuse comprising an outer casing providing a chamber for mobile insulating material, an inner casing providing a fuse chamber and communicating with said outer chamber through oppositely disposed restricted openings, and a fuse disposed in said last-named chamber extending through said openings into said outer casing, spring means exteriorly of said inner casing providing terminals for said fuse, said fuse, fuse chamber and restricted openings being so constructed and arranged that when said fuse blows the explosive force created thereby tends to force a flow of mobile insulating material through said restricted opening which carries the free ends of said fuse therewith thereby increasing the fuse 8 D- 23. A fuse comprising an outer casing providing a chamber for mobile insulating material, an inner casing providing a fuse chamber and communicating with said outer chamber through a restricted opening, and a fuse disposed in said last-named chamber extending into said restricted opening and having spring means providing terminals therefor exteriorly of said inner casing, said fuse, fuse chamber and restricted opening being so constructed and arranged that when said fuse blows the explosive force created thereby tends to extinguish the arc and force a flow of mobile insulating material through said restricted opening thereby increasing the arc gap and assisting in extinguishing the arc.

ANDREW E. PAPP. 

